Heat-Treated Sucuk in Natural Casings: A Source of Higher Fermentative and Oxidative Volatile Compounds?

The effect of the type of casing on the quality parameters of Turkish-style sausages (sucuk) is quite unexplored. So, this study aims to compare the effects of using natural or collagen casings in the production of naturally fermented (traditional) or heat-treated sucuks on physicochemical properties (moisture, acidity, pH, and color values) and volatile compounds (VCs). The VCs, extracted by a solid-phase-micro-extraction technique, were analyzed by gas chromatography-mass spectrophotometry (SPME-GC-MS). Natural casing yielded a final product with the lowest pH, highest lightness, and redness in the traditional method, and the highest moisture and browning index in the heat-treated method. Regardless of casing type, the traditional method produced sucuks with lower moisture, pH, a*, and browning index values. Cumin aldehyde, methyl eugenol, γ-terpinene, pinene, and eugenol were the most abundant VCs identified in sucuk. The type of casing did not alter the volatile profile of naturally fermented sucuk. However, in heat-treated sucuk, natural casing resulted in a higher accumulation of aldehydes, acids, and ketones in the final product compared to collagen casing. It is highlighted that natural casing may not be suitable for heat-treated sucuk due to the abundance of lipid oxidation products. Principal component analysis showed that VCs were useful in differentiating between production stages and casing types, particularly for heat-treated sucuk. This study demonstrates the impact of casing type on the quality of Turkish-style sucuk and provides a theoretical basis for casing selection in future industrial production.